The announcement came earlier Monday when the Center for Green Schools released its first ever Best of Green Schools list.

“I’ve been to hundreds of schools across the country,” Rachel Gutter, director of the U.S. Building Council’s Center for Green Schools told the Philadelphia Inquirer. “It was not a difficult choice to put Philadelphia at the top of this list.”

The district won the award based on sustainable techniques that will immediately help the environment rather than huge projects like solar panels, or as Gutter says “eco-bling,” which take a long time to show results.

“What makes Philadelphia’s efforts really smart is that they’re really focused on things that will immediately make the biggest difference for the environment as well as the students’ and teachers’ health.” Gutter told the Inky. “So they’re looking at things like green cleaning products, increased amounts of daylight.”

The organization recognized Thurgood Marshall Elementary School for meeting the highest standards for Leadership in Energy and Environment Design. Some of the school’s sustainable techniques include microfiber mops to replace wet-mop buckets and rechargeable batteries for lawn mowers and other gardening equipment.

Fellow green-school Kensington High School for the Creative and Performing Arts built a green roof using plants to conserve rainwater.